There is a solar battery module having a configuration such that a transparent substrate (glass) is arranged on a light receiving side, a plurality of solar battery cells connected to each other serially or in parallel are arranged on a back surface side of the transparent substrate, these solar battery cells are sealed by a sealing resin, so that a solar battery panel is configured, and a frame is further mounted on a peripheral edge of the solar battery panel.
A solar battery module is generally installed on a building such as a house or a structure and is exposed to wind and rain. Because the solar battery module is a product used in such a severe environment, the strength with respect to a wind load or a snow load is one of indicators representing the product quality. In recent years, to reduce a price per unit output, a time required for a constructing operation, and a time required for a wiring operation, a solar battery module has been enlarged. Because of the enlargement, the withstand load performance of a solar battery panel, particularly that of a transparent substrate of the panel, is reduced.
A snow load by snow accumulated on a surface of the solar battery module acts thereon so as to press it vertically downward, so that the solar battery module deflects downward. To handle this problem, it is known to provide, in addition to frames surrounding four sides of a solar battery panel, a reinforcement frame that is placed on a back surface of the solar battery panel so as to be laid between the frames for supporting the solar battery panel from the back surface. According to such a configuration, a decrease in deformation amount of a transparent substrate when a load is applied thereto can be expected.
In addition, according to the solar battery module having the reinforcement frame mentioned above on a back surface of a panel, in order to further prevent wear of a back sheet and breakage of cells caused by collision and friction of the back surface of the panel with the reinforcement frame, a buffer material is mounted on the back surface of the panel. Because of such a configuration, the back surface of the module does not contact the reinforcement frame directly, and thus breakage and wear of the back surface of the module can be prevented (see, for example, Patent Literature 1).